Field of the Invention
The invention relates to an apparatus for leak detection and leak location in a nuclear plant, in particular in a pipeline of a nuclear plant, having a collection line which is permeable to a substance to be detected and communicates with a pump and with a sensor for the substance, and in which the sensor is not suited to detecting the radioactivity of the substance.
The invention also relates to a method for detecting and locating leaks in a nuclear plant, in particular in a pipeline of a nuclear plant, in which the concentration of a substance from the plant that has penetrated a collection line is measured.
German Published, Non-Prosecuted Patent Application 24 31 907 corresponding to U.S. Pat. Ser. No. 3,977,233, discloses an apparatus for leakage detection and location (which is abbreviated as LEOS). That apparatus includes a collection line which is permeable to the substances to be detected. Communicating with the collection line is a pump, with which volumes of a transport medium, such as air, are pumped in succession through the collection line. Disposed at the end of the collection line is at least one sensor, which detects substances that have penetrated the collection line.
A special construction of such a collection line is known from European Patent 0 175 219 B1. It has permeable points, which may be formed of sintered metal and are spaced apart from one another. The line is impermeable between those permeable points.
U.S. Pat. No. 5,301,538 describes a further leak detecting and locating apparatus, which has at least two collection lines permeable to substances to be detected. The collection lines discharge into a common gas sensor, which in particular may be a sensor for radioactive radiation. In particular, there may be two gas sensors.
A device for monitoring a line in which radioactive substances are carried, is known from Published Japanese Patent Application JP 59 166 986. That line is surrounded by a collection line of larger diameter, which communicates with a radioactivity detector.